1. Field of the Invention
The present invention relates to brake disks for a vehicle, to a method of manufacturing the brake disks, and to a vehicle incorporating the brake disks. More particularly, the present invention relates to a method of manufacturing brake disks for front and rear wheels of a saddle-type vehicle by cutting out an intermediate portion of a disk member in a diametrical direction thereof, as well as to brake disks which are a product of the described method, and to a vehicle incorporating such brake disks.
2. Description of the Background Art
There is a known a brake disk having an outer circumference thereof including a wave shape, for a motorcycle, e.g., a conventional saddle-type vehicle. The appearance of a brake disk can be improved, and a cooling performance thereof can be raised when the brake disk is formed as a wave disk, i.e., the brake disk having a wave portion. An example of such brake disk is disclosed in Japanese Patent Laid-Open No. 2005-195112.
However, although the brake disk disclosed in Japanese Patent Laid-Open No. 2005-195112 can improve the appearance of the brake disk and raise the cooling performance thereof, and also, reduce abrasion by earth and sand by scraping out earth and sand between the disk and the pads by the wave portion of the brake disk, the productivity thereof is not referred to. In other words, the productivity of such brake disks is low.
Generally, when a wave disk having such a conventional structure, for example, as described in the Japanese Patent Laid-Open No. 2005-195112, is adopted for a front wheel (FR) and a rear wheel (RR) of a motorcycle, since the brake disks for the front wheel FR and the rear wheel RR are separately manufactured by blanking from (cutting out) different plate materials by a press, and the left-over plate materials remaining after the brake disks are blanked by the press are often abandoned. In other words, much material waste is brought about, and there is a problem in achieving a desired productivity yield at reduced manufacturing and material costs.
The present invention has been made to overcome such drawbacks of existing methods of manufacturing brake disks for the front and rear wheels of a vehicle. Accordingly, it is one of the objects of the present invention provide wave-shaped brake disks for the front and rear wheels of the vehicle, and a method of manufacturing the wave-shaped brake disks, which can improve the production yield of the brake disks.